lecture 12: population ecology & ecosystem...– boreal forest (=hutan cemara) – temperate...

LECTURE 12: POPULATION ECOLOGY & ECOSYSTEM

��

��

��

KRT-2008 1

��

��

Population Ecology

KRT-2008 2

Ecology is the study of interactions among organisms

and their environment

• Not concerned with individuals

KRT-2008 3

• Not concerned with individuals• Populations - same area, same time• Population ecology - looks at the

dynamics of populations that are similar between species

• Population density - number of individuals of a given species in a specific area at a given time

• Range - geographic area or limit of a population• Dispersion - frequency or patterns of individuals

within a range:• uniform

KRT-2008 4

• random• clumped

Population change

• Growth rate = births - deaths +immigration - emigration

• Doubling rate (time it takes for a population to double) = 0.7/growth rate

KRT-2008 5

population to double) = 0.7/growth rate (see page 911)

• Biotic potential = maximum rate of population growth given ideal circumstances

Limits on growth• Environmental resistance - combination

of the limiting factors and effects• Limiting Factors - any resource or

requirement that acts to limit population when in short supply

KRT-2008 6

when in short supply• Carrying capacity (K) - the greatest

population that can be maintained indefinitely by a given system or place

Density dependent factors• As population increases the rate of

growth is slowed by density dependent factors either by increasing the death rate or decreasing the birth rate

KRT-2008 7

decreasing the birth rate• predation, disease, intraspecifc

(within a species) competition and interspecific competition

Density independent factors

• Weather events• Natural disasters (=bencana alam)

KRT-2008 8

Survival tactics - reproduction• r strategies - (r = growth rate) - small

body size, large brood, short life span, may be opportunistic and found in disturbed or variable environments

KRT-2008 9

environments• K strategies - (K=carrying capacity) -

large body small brood, long life, care for young, constant or stable environments

Human population growth

• 1800 human population reaches 1 billion

• 1930 - in 130 years 2 billion• 1960 - in 30 years 3 billion

KRT-2008 10

• 1960 - in 30 years 3 billion• 1975 - in 15 years 4 billion• 1987 - in 12 years 5 billion• 1999 - in 12 years 6 billion

What are the density dependent limits to growth

KRT-2008 11

dependent limits to growth acting on human population?

Demographic transition• Preindustrial stage - high birth and

death rates - slow population growth • transitional stage - lower death rate

but birth rate remains high - rapid population growth

KRT-2008 12

population growth• industrial stage - birth rate declines -

rate of growth slows• post industrial stage - low birth and

death rates

Communities of organisms

• Producers - autotrophs• Consumers - heterotrophs• primary and secondary

KRT-2008 13

• Decomposers - heterotrophs

Producers in an EcosystemCategories of Organism in an ecosystem

• Autotrophs – self-nourished species (e.g. plants)

• Heterotrophs – other-nourished species

KRT-2008 14

• Heterotrophs – other-nourished species (humans and animals)

1. Producers: Green Plants responsible for photosynthesis and the release of energy into an ecosystem.

��

KRT-2008 15

� �� ! ��

No organism lives in isolation. Every living thing is

part of a community.

• Predation – pursuit (=mengejar) and ambush (menyerang)

KRT-2008 16

ambush (menyerang)• Defenses (=bertahan) – camouflage

(=menyamar), chemical defense, mimicry - (batesian mimicry or mullerian mimicry)

��

Plants compete amongst themselves for:1. water, 2. nutrients 3. sunlight and 4. space

Animals compete over1. food, 2. water, 3. mating and 4. territory

KRT-2008 17

2 main types of relationships – Predation – one species (the predator) feeds on

the other (prey) e.g. cat and mouse– Symbiosis – species live in an intimate

association with each other

�� • Parasitism - one species feeds on another

(the host) and may kill it.

• Mutualism – both parties benefit equally

KRT-2008 18

• Mutualism – both parties benefit equally from the relationship (flowers and butterflies)

• Commensalism – the relationship benefits one species but neither helps nor harms the other

Mutualism

• A symbiotic relationship• both partners benefit

– rhizobium bacteria and plants– pilot fish and sharks (=ikan hiu)?

KRT-2008 19

– pilot fish and sharks (=ikan hiu)?

Commensalism

• One benefits , the other is neither harmed (=dirugikan) nor helped– epiphytes– sea ducks and sting rays (=ikan pari)

KRT-2008 20

– sea ducks and sting rays (=ikan pari)

Parasitism

• Parasite and host• pathogen - parasite that causes disease

KRT-2008 21

Niche• The ecological role of an organism is its

niche• fundamental niche - potential niche• realized niche - actual

KRT-2008 22

• interspecific competition leads to competitive exclusion - absolute overlap cannot exist in nature

Diversity in communities

• Isolated or places with harsh (=keras/kasar) environments have less diversity

• edge effect - diversity is usually

KRT-2008 23

• edge effect - diversity is usually greatest at the margins

• old communities (tropical rainforests)tend to be more diverse than new communities (Canadian shield, artic)

Succession• Primary succession - change in species

composition over time in a habitat not previously inhabited by organisms

• Pioneer community - first community to appear

KRT-2008 24

appear• Secondary succession - change in species

composition over time in a habitat already modified by previous organisms

• Climax community -

Ecosystems and Environment

KRT-2008 25

Environment

Biogeochemical cycles• All materials flow through the environment over

time - materials cycle through the environment• Comprise processes through which elements

that sustain life (water, carbon, phosphorus and nitrogen) are continuously made available to

KRT-2008 26

nitrogen) are continuously made available to living organisms.

• Nitrogen cycle• Hydrological cycle• Carbon cycle• Phosphorus cycle

Most plants depend on bacteria to supply nitrogen

KRT-2008 27

��

KRT-2008 28

� � ��

KRT-2008 29

Phosphorus Cycle

• Phosphorus is the key to energy in living organisms, for it is phosphorus that moves energy from ATP to another molecule, driving an enzymatic reaction, or cellular transport. Phosphorus is also the glue that

KRT-2008 30

transport. Phosphorus is also the glue that holds DNA together, binding deoxyribose sugars together, forming the backbone of the DNA molecule. Phosphorus does the same job in RNA.

RocksIn some cases,phosphorous will travel to a lake, and settle on the bottom. There, it may turn into sedimentary rocks, limestone, to be released millions of

KRT-2008 31

released millions of years later. So sedimentary rocks acts like a back, conserving much of the phosphorus for future eons.

Interruptions in an EcosystemCauses:a) Natural causes – volcanic eruptionsb) Human causes – e.g. construction,

agriculture, mining, etc.

KRT-2008 32

List some of the consequences that can result from an abrupt interruption in the smooth functioning of an ecosystem?

� ��

� ��

� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � ��

KRT-2008 33

� � � � � � � � � � � � � � � � � � � � � � � � �� ! " � � � � � � � #� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � ��

Energy • Energy flows through the environment• Sunlight to chlorophyll to photosynthesis

to sugars to plant biomass to….• Food chains - energy passes from one

organism to another - it is a one way trip-

KRT-2008 34

organism to another - it is a one way trip-energy passed through the environment in a linear fashion- unlike materials

Food chains• Trophic levels• Available energy and biomass

decrease at each trophic level • Gross primary productivity - rate at

which energy is captured and stored in

KRT-2008 35

which energy is captured and stored in plant tissues

• Net primary productivity - energy after plant’s requirements

��

� $ � � � � � � � � � � � � � � �� % � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � ��

� $ � � � & � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � ��

KRT-2008 36

� � � � � � � � � � � � � � � � � � � � � � � � � � � ��

� ' � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � ��

� �� ! �� ! �� ! �� ! �� "�� "�� "�� "��

KRT-2008 37

� �� ! �� ! �� ! �� ! �� "�� "�� "�� "�� "�� "�� "�� "�� #�� #�� #�� #�� $ �� $ �� $ �� $ ��

% �� % �� % �� % ��

� � � � � ��

" � ��

KRT-2008 38

" � � � � � � � �� " �� " � �� " ! � � ��! � � ��! � � ��! � � �� """"

� � ��

" � # $ � %� # $ � %� # $ � %� # $ � %

KRT-2008 39

" � # $ � %� # $ � %� # $ � %� # $ � %" � � $ �� & � ' # $� � $ �� & � ' # $� � $ �� & � ' # $� � $ �� & � ' # $" ( �� & � �� $ �( �� & � �� $ �( �� & � �� $ �( �� & � �� $ �" ) � ��' �* * �� & �) � ��' �* * �� & �) � ��' �* * �� & �) � ��' �* * �� & �+ ��+ ��+ ��+ ��

• The path of energy from one feeding level to another.

(chain reaction)

KRT-2008 40

• Which direction is the energy flow?

KRT-2008 41

What is missing from the food web?

Tertiary Consumer

SecondaryConsumer

Primary Consumer

KRT-2008 42

Decomposer

Food Pyramid

KRT-2008 43

Energy Flow• Photosynthesis explains

how energy from the sun is captured by green plants and used to make food.

• Most of this energy is used

KRT-2008 44

• Most of this energy is used to carry on the plant's life activities.

• The rest of the energy is passed on as food to the next level of the food chain.

��

KRT-2008 45

Major ecosystems• Biomes - large distinct ecosystem

– Tundra (=padang lumut)– boreal forest (=hutan cemara)– temperate rainforest– temperate deciduous forest– temperate grasslands– Chaparral (=vegetasi xerophyta /tanaman tahan

kering)

KRT-2008 46

kering) – Deserts (=daerah dengan curah hujan kurang)– Savanna (=padang rumput dengan pohon yang

bertebaran)– tropical rainforests

Factors Affecting Ecosystems• Soil• Available Water• Temperature• Sunlight

KRT-2008 47

• Abiotic factors will determine biotic factors– Climates (sunlight, temperature and rainfall)

will determine which types of vegetation can exist which will determine what type of animals can exist.

Soil• pH of soil determines which

plants grow best.• Soil Layers

– Litter - the upper layer of soil, composed mainly of partially decomposed leaves or grasses

– Topsoil - the soil layer beneath the litter, composed of small

KRT-2008 48

the litter, composed of small particles of rock mixed with humus

– Humus - decaying plant and animal matter

– Subsoil - the soil layer beneath the topsoil, usually containing more rock particles and less organic matter than the topsoil

– Bedrock - the layer beneath the soil, composed of rock

Available Water• The amount of available water is

determined by the amount and type of precipitation.

• Amounts of rainfall determined by distance form equator, mountains ranges ocean

KRT-2008 49

form equator, mountains ranges ocean and wind currents.

• The amount of available water will determine the type of vegetation that can exist

Temperature

• Plants and animals must be well adapted to the temperatures that exist within their ecosystems. – Chinophobes – snow haters (ex. Geese)– Chinoeuphores – snow adaptors (ex. Snowshoe hare)

KRT-2008 50

– Chinophiles – snow lovers (ex. Polar bears)

• Temperature also influences rates of evaporation which can influence the amount of available water.

Plant Adapted for Specific Habitats

• Xerophytes – plants that live in the desert biome

• Epiphytes – plants that are not rooted in soil but grow directly on other plants

KRT-2008 51

Aquatic ecosystems• Lakes and ponds (=danau dan kolam)

– littoral zones - nearest to shore (=tepi)– limnetic zones - open water– profundal zone (=tempat yang paling dalam) - no

light• Marine (=laut)

KRT-2008 52

– Intertidal (= bagian pantai yang terkena pasang surut) - very productive

– pelagic - open ocean– euphotic - light is present (100 m)– neritic - 100 m to 200 m– oceanic - no light

Stratification in water• In summer warm layers on top, colder

at the bottom, separated by thermocline• in fall, water turns over and some

mixing between layers occurs• in winter cold at top, warmer at bottom

KRT-2008 53

• in winter cold at top, warmer at bottom• in spring another turnover!• Spring turnover stimulates algae

growth...

Environmental effects• living factors in the environment affect the species that are present

like temperature, amount of rainfall, predation, availability of

KRT-2008 54

rainfall, predation, availability offood, and population size. As a result, organisms may evolve.

Group Discussion: Discuss each environmental effect and possible outcomes

How do organisms evolve?

• by adapting to their environments, two or more organisms evolve together.

KRT-2008 55

• To "make the best of" where they live, organisms make use of other organisms by eating them, living on or in them, and/or building a "partnership" with them.

Predation• describes an interaction where a

predator organism feeds on another living organism or

KRT-2008 56

another living organism or organisms known as prey (=mangsa).

� ��

KRT-2008 57

� � �� !��!��

� "��# ��$��# ��

KRT-2008 58

��

� % ��!��# �� &��

'��

��

KRT-2008 59

KRT-2008 60

� ��

� ��

KRT-2008 61

� � ��

� � ��

��# ��

� � ��

KRT-2008 62

� � ��

� � ��

( �# ��# ��&��

KRT-2008 63

��

� ��

�� &��

KRT-2008 64

% �� &��

� ��&��&�� # # ��

( �# ��# ��# �&��

% ��)��# ��&��# ��&&��&��# ��# ��# �&��&��

% �� )��

KRT-2008 65

% ��*��)��# ��)��

% ��*��# ��)��&��&��# ��

KRT-2008 66

� ��

% ��# ��!��!��# ��&��

�# �� # ��

KRT-2008 67

��!��)��( ��)��

��)��

% ��# ��!��# ��# ��

��&�&��)�� # +��# ��

'��)�� # ��&��

KRT-2008 68

, ��!�� # ��&�&��

-!��!��

% ��&��# ��

KRT-2008 69

��

% �� !��&��!��

, ��

��# ��

'��# ��&�� !��&��

'��

KRT-2008 70

��

. ��

( �� / ��

The Earth has many different environments, varying in temperature, moisture, light, and many other factors. Each of these habitats has distinct life forms living in it, forming complex communities of interdependent

KRT-2008 71

communities of interdependent organisms. A complex community of plants and animals in a region and a climate is called a biome.

•Desert - very dry, either hot or cold •Tundra - cool, treeless, and dry •Chaparral or scrub - coastal area with hot, dry summers and mild, cool, rainy winters •Taiga or Coniferous Forest - cool and dry, with coniferous trees •Temperate Deciduous Forest - cool and rainy, with deciduous trees •Grassland - Windy, partly dry sea of grass with few trees, including tropical savanna, prairie, steppe, pampas, etc. •Mountina biomes: there are a lot of different biomes that exist on a mountains, from grasslands at low altitudes, taiga (coniferous forests) below the treeline, and alpine (the same as tundra) •Temperate Rain Forest - cool and wet

Some of the biomes on Earth include:

KRT-2008 72

•Temperate Rain Forest - cool and wet •Tropical Rain Forest - warm and very wet •Land Caves - cool and dark •Wetlands - there are many types of wetlands, including swamps, marshes, moors, bogs, fens, sloughs, etc. •Freshwater Marsh - a wetland located near creeks, streams, rivers and lakes •Temperate ponds•Marine (ocean or sea) - including benthic biomes (bottom), coral reef (warm shallow salt-water environments based on coral formation), pelagic biomes (open seas near the surface), littoral or intertidal zones, estuarine biomes (where rivers meet oceans), etc. •Sea Caves.

Deserts

• Little rainfall• High evaporation• Low humidity• Biodiverse

KRT-2008 73

• Biodiverse• Arid or semiarid• Desertification

Dry Shrublands, Woodlands, and Grasslands

• Drought and fires• More rain than

deserts• Drought-tolerant

KRT-2008 74

• Drought-tolerant plants

• Hot summers, cold winters

• Chaparral• Savannas

– Grazing animals

Tropical Rain Forests and Broadleaf Forests

• Canopy Trees• Evergreen Broadleafs

– Tropical rain forests– Rapid decomposition and mineral cycling

KRT-2008 75

– Rapid decomposition and mineral cycling– Humus poor

• Deciduous Broadleafs– Leaves drop– Tropical and Temperate Forests– Decomposition not as rapid

Tropical Rain Forests and Broadleaf Forests

KRT-2008 76

Coniferous Forests

• Canopy Trees– Coniferous

– Boreal

– Southern pine

KRT-2008 77

– Southern pine

– Evergreen Conifers

Tundra

• Treeless plain between polar ice cap and boreal forests

• Cool short summers

KRT-2008 78

• Cool short summers

• Below freezing winters

• Sunlight nearly continuous in summers

• Permafrost

Lake Ecosystems

Standing freshwater

KRT-2008 79

Seasonal Changes in Lakes

• Changes in density and temperature

• Spring

KRT-2008 80

• Spring overturn

• Fall overturn

Seasonal Variation in Primary Production in Oceans

Phytoplankton blooms

KRT-2008 81

Upwelling Along Coasts in the Northern Hemisphere

KRT-2008 82

Environmental Issues• Habitat destruction• pollution• foreign or exotic species• deforestation

KRT-2008 83

• global warming• ozone depletion

KRT-2008 84

lecture 12: population ecology & ecosystem...– boreal forest (=hutan cemara) – temperate...

Documents